This invention relates to an electrical junction box in which a circuit board is contained in a casing.
Heretofore, an electrical junction box that is mounted in a motor vehicle to supply and shut out electrical currents to on-vehicle electrical components such as lamps and horns has been known, as disclosed in Patent Document 1. The electrical junction box contains in a casing a circuit board on which electronic parts are mounted. An upper part of the casing is provided with a mounting section that is open upward and is adapted to receive a mating member such as a connector.
For example, in the case where the electrical junction box is contained in an engine compartment in a motor vehicle, when water falls down onto the electrical junction box upon raining or vehicle-washing, there is a possibility that water will enter the casing through the mounting section provided on an upper part of the casing.
In the electrical junction box, connecting terminals are contained in the mounting section and are connected to a connector body, and the connector body is provided below the mounting section. An upper surface of the connector body is provided with a slope that drains water, which has entered the casing, through an end of the connector body. An end of the slope defines a drainage port. A duct is provided below the drainage port to be open downward, so that the water that has drained from the drainage port is drained out of the casing.    [Patent Document] JP 2003-348732 A
However, according to the above construction, there is a possibility that the water that has reached the drainage port will flow around a lower surface of the connector body and will move toward the circuit board. Then, the water will attach to the circuit board to cause a short circuit in a circuit formed on the circuit board.
In view of the above problems, an object of the present invention is to provide an electrical junction box that can prevent water in a casing from attaching to a circuit board.